当我尝试引用图形时，例如“参见图~\ref{lattice1}”，输出为“图??”。我标记错了吗？

Question

\documentclass{article}
 \begin{document}

\begin{figure} %

\begin{subfigure}[b]{0.30\textwidth}
\centering

\begin{tikzpicture}[
  decoration={
    markings,
    mark=between positions 0 and 1 step 25pt with { \draw [fill] (0,0) circle [radius=2pt];}
  }
]
\path[postaction={decorate}] (0,4) to (4,4);
\path[postaction={decorate}] (0,3) to (4,3);
\path[postaction={decorate}] (0,2) to (4,2);
\path[postaction={decorate}] (0,1) to (4,1);
\path[postaction={decorate}] (0,0) to (4,0);
\draw [<->] (2.3,2) -- (1.75,2) -- (1.75,2.65);
\draw [dashed] (0, 1.5) -- (4,1.5);
\draw [dashed] (0, 2.5) -- (4,2.5);
\end{tikzpicture} 
\label{lattice1}
\caption{A lattice of sources. Equation~(\ref{G01}) is the field generated by the central row.}
\end{subfigure} %
\begin{subfigure}[b]{0.30\textwidth}
\centering
\begin{tikzpicture}[
  decoration={
    markings,
    mark=between positions 0 and 1 step 25pt with { \draw [fill] (0,0) circle [radius=2pt];}
  }
]
\path[postaction={decorate}] (0,4) to (4,4);
\path[postaction={decorate}] (0,3) to (4,3);
\path[postaction={decorate}] (0,2) to (4,2);
\path[postaction={decorate}] (0,1) to (4,1);
\path[postaction={decorate}] (0,0) to (4,0);
\draw [<->] (2.3,2) -- (1.75,2) -- (1.75,2.65);
\draw [dashed] (1.25,0) -- (1.25,4);
\draw [dashed] (2.25,0) -- (2.25,4);
\end{tikzpicture}
\label{lattice2}
\caption{A lattice of sources. Equation~(\ref{F0}) is the field generated by the central column.}
\end{subfigure} %
\begin{subfigure}[b]{0.30\textwidth}
\centering
\begin{tikzpicture}[
  decoration={
    markings,
    mark=between positions 0 and 1 step 25pt with { \draw [fill] (0,0) circle [radius=2pt];}
  }
]
\path[postaction={decorate}] (0,4) to (4,4);
\path[postaction={decorate}] (0,3) to (4,3);
\path[postaction={decorate}] (0,2) to (4,2);
\path[postaction={decorate}] (0,1) to (4,1);
\path[postaction={decorate}] (0,0) to (4,0);
\draw [<->] (2.3,2) -- (1.75,2) -- (1.75,2.65);
\draw [dashed] (1.25,0) -- (1.25,4);
\draw [dashed] (2.25,0) -- (2.25,4);
\draw [dashed] (0, 1.5) -- (4,1.5);
\draw [dashed] (0, 2.5) -- (4,2.5);
\end{tikzpicture} 
\label{lattice3}
\caption{A lattice of sources. Equation~(\ref{G0}) is the field generated close to the central source.}
\end{subfigure} %
\label{lattice}

\end{figure}

\end{document}

Answer 1

您必须对您的文档进行两次编译。

第一次您将创建一些文件。它们指示您有标签、部分的位置...

因此第二次引用将出现